1 Introduction

Bertrand Russell was already something of a celebrity when he visited Harvard University in 1914. He and A. N. Whitehead had just completed their three-volume Principia Mathematica. He had been one of the first to employ the new logic to tackle philosophical problems. And he was one of the best-known opponents of William James’ theory of truth. Naturally, Harvard was eager to acquire the British professor who had started to receive “more attention than any logician since Aristotle” (Lenzen 1971, 4). Ralph Barton Perry, chair of the department, invited Russell for a visiting position; and Josiah Royce, one of America’s prime logicians, travelled to Cambridge to ask Russell to accept a permanent post, an offer Perry repeated as soon as he arrived in the United States.¹

Russell visited “the other Cambridge” in a crucial period in the history of Harvard philosophy. The department had, in Russell’s view, been “the best in the world” ([1944–1967] 1975, 205) but it had lost three of its professors in a few years’ time. James had died, George Santayana had moved to Europe, and Royce had suffered a mild stroke. Though Russell had received Harvard’s first invitation when all three were still active (Griffin 1992, 441), the department was in a state of deep crisis when he arrived in March 1914. So much so, that he rapidly grew tired of the stories about its tragic fate. In his autobiography, Russell writes:

Every professor … made me the following speech: ‘Our philosophical faculty, Dr. Russell … has lately suffered three great losses. We have lost our esteemed colleague, Professor William James, through his lamented death; Professor Santayana … has taken up his residence in Europe; last, but not least, Professor Royce, who, I am happy to say, is still with us, has had a stroke.’ This speech was delivered slowly, seriously, and pompously. The time came when I felt that I must do something about it. So the next time that I was introduced to a professor, I rattled off the speech myself at top speed. This device, however, proved worthless. ‘Yes, Dr. Russell,’ the professor replied: ‘As you very justly observe, our philosophical faculty …’ and so the speech went on to its inexorable conclusion. (Russell [1944–1967] 1975, 205)

Russell’s three-month visit proved an ideal occasion to fill the void created by the department’s intellectual decapitation. He persuaded Perry “that logic is the important thing” in philosophy, taught courses on epistemology and the Principia, and advertised his “logical-analytic method” to an audience of over five hundred people.² Symbolic logic had already played some role at Harvard due to Royce and the influence of C. S. Peirce. But its impact had been rather limited in a department that valued doctrinal and methodological pluralism (Palmer and Perry 1930). In the years following Russell’s visit, however, Harvard significantly changed its focus. The department hired H. M. Sheffer (in 1917), C. I. Lewis (1921), and Whitehead (1924), all well-known for their contributions to the discipline, and Harvard quickly became known as the “center of formal logic in the United States” (Morris 1935, 146). Whereas James had once confessed that he was “a-logical, if not illogical, and glad to be so”, Harvard faculty noted “an unmistakable drift in the direction of logic” by the late 1920s.³ The new generation of Cambridge’s best and brightest—e.g., Susanne Langer, William Parry, Henry Leonard, and W. V. Quine—employed Russell’s logical-analytic method and they all “looked forward to a new philosophical era, that was to grow from logic and semantics” (Langer 1964, 306).

This paper reconstructs the development of the “Harvard school of logic” through the lens of Russell’s 1914 visit, tracing and contextualizing his influence on the course of American philosophy.⁴ My reconstruction is divided into two parts. The first sections sketch the U.S. philosophical landscape in the years before Russell’s visit. I examine the intellectual and institutional developments that created fertile ground for his logical-analytic approach, showing why both Royce and the Harvard “new realists” Perry and E. B. Holt saw him as the ideal successor to James (Sections 2–5). In the second half, I trace the impact of Russell’s visit on the department’s intellectual climate and hiring policy, reconstructing the growth of the Harvard school and its influence on America’s analytic turn in the subsequent decades (Sections 6–10).

2 American Idealism and the Professionalization of Philosophy

Late nineteenth century American philosophy is often associated with pragmatism. It is the period when Peirce introduced his pragmatic maxim and when James became one of the country’s most distinguished professors of philosophy. Histories of the period often start with an account of the Metaphysical Club—widely recognized as the cradle of pragmatism—and scholars sometimes refer to the era as the “golden age of American philosophy” (Frankel 1960). We should be careful, however, not to project our current associations back onto the history of philosophy. Though there are good reasons to trace the origins of pragmatism to the 1870s and 1880s, it only became a subject of serious debate in the early 1900s, when James’ and Dewey’s publications sparked an international discussion about pragmatist theories of truth and inquiry. Nobody self-identified as a “pragmatist” until 1898, when James first embraced the pragmatic maxim (James 1898), and Peirce’s work was only influential in a small circle until the publication of his collected papers in the 1920s and 1930s (Misak 2024).

Though it may be accurate to describe the broad, intellectual climate as congenial to what we nowadays label as pragmatist views, the late nineteenth century American landscape was in many ways similar to the environment Russell encountered when he and Moore started a revolt against idealism in England. American philosophy, publications from the period reveal, was also dominated by idealism.⁵ Mary Whiton Calkins, for example, maintained that “the trend of philosophy” was “so clearly toward idealism, that the modern issues lie altogether between one idealistic system and another” (Calkins 1907, 404; see also Montague 1907, 100; Thilly 1914, 549). Calkins distinguished a few “non-idealistic positions” including the “materialist” doctrine that all of reality, including the human mind, is material in nature, but added that such views were not taken seriously by practiced philosophers (Calkins 1907, 400). They were defended by scientists such as Ludwig Büchner and Ernst Haeckel, whose ideas were to be viewed as “purely popular half-thought”, offering no convincing reply to the idealist thesis that reality is mind-dependent (Calkins 1907, 404).

A similar emphasis on idealism can also be found in foreign overviews of American philosophy. In his 1904 La philosophie en Amérique, Edward van Becelaere wrote that “the great number of contemporary American thinkers belong, in one form or another, to the idealist school” and he identified German idealists such as Hegel and Hermann Lotze as some of “the most authoritative philosophers among American thinkers” (1904, 105, my translation). Though van Becelaere, a Catholic minister, described the United States as a deeply materialist country in which the “positivistic tendency is … so accentuated” that the “educated public has paid little attention to matters of speculative philosophy”, he emphasized that the intellectual climate was substantially different in academic quarters:

Today, strange as it may seem to those who want to see only … materialist tendencies in the American character and spirit, it is an undeniable fact that idealism remains the dominant type of speculative thought, at least in the domain of Metaphysics. (Van Becelaere 1904, 105, my translation)

G. Stanley Hall, one of Peirce’s former colleagues at Johns Hopkins, signaled a similar tension between a materialist culture and idealist academics in his overview article “Philosophy in the United States”. Recognizing the influence of the scientists whose work Calkins dismissed as “purely popular half-thought”, he also highlighted the “very great” impact of idealism, noting above all “the influence of Hegel” on American philosophers (Hall 1879, 104).

Idealists dominated American philosophy during a highly transformative period. Whereas the philosophical climate had once been shaped by theologians and public intellectuals, the study of philosophy professionalized into a distinct and clearly delineated academic discipline in the late nineteenth century. American philosophers started the first professional philosophy journals—e.g., International Journal of Ethics (1890) and Philosophical Review (1892)—and they founded academic societies such as the Western Philosophical Association (WPA, in 1900) and the American Philosophical Association (APA, in 1901).⁶ These developments were partly a response to the professionalization of American higher education more generally. While New England colleges had been small and religious institutions up until the 1870s, American academia radically changed in the last decades of the nineteenth century. The rapid industrialization of the U.S. economy not only created the wealth to establish and endow new institutes for higher education, it also changed the country’s view about the type of graduates it needed (Veysey 1965). The Morrill Act of 1862 granted states federally owned land to raise funds to establish colleges with a more technological or agricultural focus and self-made industrialists like Andrew Carnegie endowed the first research universities and polytechnics. Institutions democratized, started to offer graduate level education, and began focusing on research and publication.

Harvard, America’s oldest and most prestigious college, was one of the front runners of this development. Between 1869 and 1909, the period when Charles William Eliot served as its president, Harvard grew from a small though preeminent school with 59 staff members to an internationally esteemed research university with 610 professors and instructors (James 1930, 347). Eliot gradually raised admission standards and implemented a system of electives such that students could select their own courses, an innovation that made teaching at Harvard more appealing to specialists. Harvard’s department of philosophy especially changed as a result of these developments. Eliot, who had a scientific background and was the university’s first secularly oriented president, believed that the traditional mode of teaching was “appropriate in a convent or a seminary for priests” but “intolerable in universities” (James 1930, 231). He transferred James’ course on physiology and psychology to the philosophy department (Kuklick 1977, 134–35) and helped appoint several other scholars, e.g., George Herbert Palmer, Hugo Münsterberg, and the aforementioned Royce, who would help make Harvard’s department of philosophy the “best in the world” (Russell [1944–1967] 1975, 205).

It is no coincidence that the professionalization of American academia went hand in hand with the increasing dominance of idealist thought in academic philosophy. For the two developments had a common cause. Because most American schools offered only college level education for much of the nineteenth century, many U.S. academics had studied in Germany (Werner 2013, 8). It was in Germany that these students experienced the benefits of an academic system characterized by Lehrfreiheit and Lernfreiheit, or the freedom to teach and study the topics one is actually interested in (Geiger 2015, 328). And it was in Germany that they became acquainted with the latest developments in science, mathematics, and speculative philosophy. It was the country, in Eliot’s words, “whose scholars and universities” had “for a century given example and inspiration to the learned world” (cited in James 1930, 99).⁷ Royce, who spent time at the universities of Heidelberg, Leipzig, and Göttingen, remembers:

[I]n those days there was a generation that dreamed of nothing but the German University … German scholarship was our master and our guide … The admirable hospitality of the German University toward the foreign student fostered this enthusiasm. … [T]he American student found himself able to come into immediate contact, as it were, with the great minds of the German world of scholarship. (Royce 1891, 382–83)

The professionalization of academia and the rise of speculative philosophy were so intricately connected that the term “idealism” acquired a much richer meaning than the philosophical doctrines we associate with it today. To be an idealist was not just to accept the thesis that reality depends on the knowing subject, it was to pursue pure philosophy and to liberate oneself from the strictures of the traditional educational system. In the words of Royce: “One went to Germany still as doubter as to the possibility of the theoretic life; one returned an idealist, devoted for the time to pure learning for learning’s sake, determined to contribute … to the massive story of human knowledge, burning for a chance to help build the American University” (Royce 1891, 383).

It is hardly a surprise, therefore, that the idealists played an important role in the professionalization of American philosophy. The two American editors of International Journal of Ethics, Royce and Felix Adler, were both idealists who had studied in Germany in the 1870s, and Philosophical Review was founded by Jacob Gould Schurman and James Edwin Creighton, two speculative philosophers who had also established the Sage School at Cornell (1891), soon to become one of the centers of idealist thought in the United States. Creighton in particular would prove to be a key figure in the professionalization of academic philosophy, influencing “the form and expectations of the modern”profession” of philosophy, its role in contemporary universities, its characteristic curriculum, its professional organizations, and its form and style of publication” (Auxier 2005, 249; Katzav and Vaesen 2022). The Canadian-born philosopher who had studied in Berlin and Leipzig was not just the co-founder of Philosophical Review and the Sage School of Philosophy. He was also the American editor of Kant Studien and one of the founders of the APA, serving as its first president in the 1902–1903 academic year.⁸

3 Trojan Horse

In their attempts to secure a future for philosophy in the rapidly transforming academic system, Creighton and his idealist associates had to walk a tightrope. On the one hand, they had to position philosophy as a discipline independent from theology. Since the clerical class was rapidly losing influence in American academia, they had to convince university presidents that philosophy was not just a “useful handmaid to theology” but a “real and independent subject of investigation” (Creighton 1902, 232). Though many American philosophers were what Montague would later call “right wing” idealists whose philosophical ideas were intricately tied to their religious convictions, they approached religion in a completely different way.⁹ Instead of relying on scripture, they believed that philosophy was needed to ground and unify scientific, moral, and religious truths—i.e., that only philosophy could “investigate the grounds and principles of the whole body of truth with a view to its unity and meaning as a whole” (Ormond 1906, 3).

On the other hand, idealists felt that they had to prevent their discipline from being swallowed by the sciences, especially now that research universities and polytechnics were becoming an increasingly important force in American academia. Not only did some idealists regard the mechanistic worldview of the sciences as a theoretical threat to spiritual beliefs and universal moral values, they were also alarmed by the frequent attempts of scientists to try and answer philosophical questions. Academic philosophers, the above survey of textbooks from this period shows (Section 2), were worried about the increasing number of philosophical publications by scientists and popular science writers such as Büchner and Haeckel. In his presidential address of the first meeting of the APA in 1902, Creighton argued that philosophy had to protect itself against natural scientists who, “wholly unschooled in the subject … feel themselves competent … to write philosophical books” and to confidently proclaim their “short and easy answers to the riddles of the universe” (1902, 232).¹⁰

A large faction of the philosophical community, in sum, felt that the discipline had to “free itself from science on the one hand and religion on the other” (Woodbridge 1903, 370). Institution builders such as Creighton (1902, 237) found a middle way by positioning philosophy as a distinct academic discipline. Theoretically, philosophy was sold as a foundational study that could unify experimental, moral, and religious perspectives. Practically, they ensured philosophy’s independence through the foundation of philosophical journals and associations, meaning that American philosophers could enforce their own disciplinary standards and shield the field from scientific and theological intruders. In the aforementioned presidential address, Creighton argued that the APA’s main purpose was “to promote and encourage original investigation and publication” and to set “a high standard” for philosophical research, arguing that the philosopher is “a specially trained scholar whose opinions in his own field are as much entitled to respect as those of the physicist or biologist in his special domain” (1902, 230, 232). Likewise, the new journal Philosophical Review aimed to create a novel, purely academic, platform for philosophical discussion, driving a wedge between professional and popular philosophy. In the prefatory note to the first volume, Creighton’s colleague Schurman described the journal as a platform devoted to “special philosophical interests” and the cultivation of “special philosophical domains” (Schurman 1892, 5). Within Cornell’s Sage School, finally, Schurman and Creighton pushed for the independence of philosophy by creating a curriculum that helped to set the standard for many philosophy departments in the nation, teaching students distinctly philosophical subjects such as metaphysics, epistemology, and history of philosophy instead of grammar, rhetoric, and natural science (Auxier 2005, 552).

Logic in particular played a central role in Creighton’s view as to what distinguishes philosophy from the sciences. In his textbook An Introductory Logic (1898), one of the leading texts for American philosophy students in the first decades of the twentieth century (Cunningham 1925, 214), Creighton argued that logic is the pure study of thought, thereby distinguishing it from psychology, which he believed had “differentiated itself almost entirely from philosophy”, in becoming an experimental science:

The important difference is this: In psychology we are interested in the content of consciousness for its own sake, and just as it stands. We try to find out what actually goes on in our minds, and to describe it just as we should any event which occurs in the external world. But in logic the question is not: What are mental processes? but rather: What knowledge do they give us, and is this knowledge true or false? Logic, in other words, does not regard the way in which ideas exist, and is not interested in them for what they are, but rather in the purpose which they subserve in affording us knowledge of something beyond themselves. (Creighton 1898, vi, 5)

Whereas psychology and related disciplines had increasingly come “under the influence of experimental methods”, logic was the key instrument in the philosopher’s toolbox (Creighton 1898, vi).

Ironically, the idealists would contribute to their own demise in professionalizing philosophy. While their journals and societies had been founded to safeguard philosophy’s independence, they also helped create an institutional structure that had worked particularly well in the sciences. Intellectual generalists and speculative system builders still dictated the philosophical conversation in the late nineteenth century but the next generation developed a new academic culture, making use of the very journals their teachers had founded in order to prevent the discipline from being swallowed by the sciences. In viewing philosophers as “specially trained scholars” (Schurman 1892, 5), they opened the door to a new conception of philosophy, one which was more focused on “definitive intellectual solutions to specific problems” (Cohen 1921, 264). And in promoting the use of philosophy journals, they stimulated the publication of “technically specialized research published for technically competent audiences” (Wilson 1990, 124). Most importantly, by placing logic at the heart of academic philosophy, they helped create a structure that would soon be gratefully exploited by philosophers who had a very different conception of logic. Whereas Creighton and many fellow speculative philosophers conceived of logic in idealist terms, it would be the “mathematical” logic of Peirce and Russell that captured the interest of the next generation.¹¹ In their attempts to distinguish philosophy from science, in other words, they created the institutional space for formal logic to become a major force in academic philosophy.¹²

4 Revolt

In England, the revolt against idealism was led by Moore and Russell, two recent Cambridge graduates who objected to Bradley’s absolute idealism and sought to replace it with a variant of realism. In the United States, something remarkably similar happened. Two recent graduates from “the other Cambridge”, William Pepperell Montague and Ralph Barton Perry, objected to the philosophy of Royce, America’s best-known absolute idealist. Following their former teacher James, who had criticized Royce’s ideas from a pragmatist point of view, they advanced a realist position that was fundamentally opposed to Royce’s thesis that the reality of everyday experience has no existence independent of a knowing subject. Within three months from each other, Montague and Perry published the similarly titled papers “Professor Royce’s Refutation of Realism” (1902) and “Professor Royce’s Refutation of Realism and Pluralism” (1902), arguing that the idealist’s attempts to portray realism as a philosophical dead end failed. Royce (1899, 62) had characterized realism as the view that mind-independence is “the very essence” of reality and he had argued that it is impossible to have knowledge about the world on such an account. If realists believe that reality is necessarily mind-independent, Royce maintained, we are by definition excluded from access to the external world. Perry, however, objected to Royce’s characterization of realism, arguing that realists do not define reality in terms of its relation to consciousness:

[I]t would seem that [Royce] means by realism the proposition that reality is essentially independen[t] of any form of consciousness. Such a definition, however, represents neither common sense nor any historical type of philosophy. … [Realism] is a positive ontology, and not a negative epistemology. (Perry 1902, 449, my emphasis)

Montague, also a Harvard graduate, developed a similar objection. Royce, he maintained, confuses the realists’ “ratio cognoscenti” with its “ratio essendi”: an object’s independence “is not what makes it real, it is what makes us aware that it is real” (1902, 45).

At first, the American revolt against idealism was mostly formulated in negative terms. Montague and Perry dismissed Royce’s anti-realist arguments but they did not specify how we know the world without it depending on us knowing it (Kuklick 1977, 339). By the end of the decade, however, they had started a “new realist” movement with a positive philosophical agenda. Six realist philosophers, Montague, Perry, Edwin Bissell Holt, Walter Taylor Marvin, Walter Boughton Pitkin, and Edward Gleason Spaulding, joined forces and co-authored a manifesto (“A Program and First Platform of Six Realists,” 1910) and a book (The New Realism, 1912). They described their realism as “new” because they did not want to return to the “representational” realism of their predecessors. Philosophers such as Locke had posited the existence of “ideas” as an intermediary between consciousness and the world in order to solve the problem of “error and illusion”: true ideas accurately represent reality but when we are hallucinating there is no correspondence between our ideas and the mind-independent world (1912, 4). But according to the new realists, it was this “idea idea” that had given rise to the sceptical thesis that we have no direct access to the external world and, still later, to the idealist proposal that reality is mind-dependent. The six philosophers wanted to develop a new, “presentational” realism that could avoid both the scepticism and idealism of their predecessors without opening themselves up to the problem of illusion. They believed they could achieve these goals by inquiring “closely into the mechanism of perception, and into the logic of contradiction and falsity” (1912, 11).

For our present purposes, it is important to note that new realism was more than a set of philosophical doctrines. The movement also aimed to promote a new way of doing philosophy. The six realists argued for a more scientific, collaborative, and logic-infused approach to philosophy. Whereas their idealist predecessors had been solitary system builders who presupposed a strict distinction between positive (scientific) knowledge and philosophical synthesis, they viewed themselves as part of an “era of united and complimentary endeavor” (1912, 21). They promoted the use of logic and analysis and advocated a piecemeal approach, dealing with “one problem at a time” instead of attempting to “raise and answer all questions together” in a comprehensive philosophical system (1912, 21–26). Like the idealists, they distinguished between the experimental method of the sciences and the logical methods of philosophy; but unlike the idealists, they were keen to emphasize the fruits of modern, symbolic logic. The new realists believed that many of the idealists’ arguments were based on logical fallacy or “verbal abuse” and they appealed to the new logic to develop a theory that could avoid these mistakes (1912, 11–20):

Logic is at the present time in a state of extraordinary activity, and able both to stimulate and to enrich philosophy … The theory of relations, the theory of ‘logical constants’ or indefinables, the theory of infinity and continuity, and the theory of classes and systems, concern everything fundamental in philosophy. No philosopher can ignore these and like theories without playing the part of an amateur. … The present situation is certainly intolerable; for philosophy deals with the same topics as modern logic, but treats popularly and confusedly what modern logic treats with the painstaking thoroughness and exactness of the expert. (Holt, Marvin, Montague, Perry, Pitkin, and Spaulding 1912, 25–26)

The movement even had an organ to develop its philosophical program: the newly-founded Journal of Philosophy, Psychology, and Scientific Methods (later Journal of Philosophy). The periodical, edited by Montague’s colleague F. J. E. Woodbridge, played a major role in challenging the dominance of idealist philosophy. In a letter to Perry, Pitkin wrote that Woodbridge had agreed that he and the other five realists could “thrash out any topic though its columns”.¹³ The journal published almost forty papers of the six realists in the early 1900s and regularly advertised itself as a journal “in the field of scientific philosophy”.¹⁴ Excited about this new wave of scientific philosophy, Morris Cohen even argued that the journal represented the next Comtean stage in the history of U.S. philosophy. Whereas the founding of Philosophical Review had represented the start of the speculative period in American thought, the founding of this new journal exemplified the start of the scientific era of U.S. philosophy (Cohen 1910, 401–02).

Conceptually, a realist metaphysics does not necessarily commit one to a scientific approach to philosophy. In principle, one can also use the tools of traditional, speculative philosophy to defend a realist position. Historically, however, it is no coincidence that the six realists advocated the use of analysis and symbolic logic. For Russell had been doing the same thing in England. Though Perry and Montague developed their initial arguments independently of their British colleagues, they were quick to note that similar things were happening in England. Perry reviewed Moore’s “The Refutation of Idealism” in 1904 and Montague explicitly mentions the “vigorous revival of realism on the part of Mr. G. E. Moore and Mr. Bertrand Russell” in a paper titled “Current Misconceptions of Realism” (Perry 1907). Many American realists were encouraged and inspired by Moore and Russell and started to use their arguments and methods in their own work. Logical tools played a crucial role in the writings of Perry and Spaulding; and Holt presented his theory of consciousness as a direct consequence of the new logic, using the first four chapters of his book The Concept of Consciousness to discuss the nature and development of symbolic logic.¹⁵

Russell’s theory of relations played an especially important role in the neo-realists’ arguments. Absolute idealists had assumed that “relations are always grounded in the natures of their terms” (Russell 1907, 28) and, hence, that a statement like “Anne and Blake are born on the same day” tells us something about the nature of Anne. Russell, however, had rejected the assumption and replaced it with the view that relations are “external” to the relata: the fact that Anne and Blake are born on the same day tells us something about the relation between Anne and Blake, not about the nature of Anne. But whereas Russell had primarily used his view to argue against Bradley’s absolutism—the view that there is just one absolute truth, not a multitude of particular truths (Russell 1907, 28)—the neo-realists employed it to argue against idealism. In response to the idealist argument that objects are essentially mind-dependent, Perry objected that speculative philosophers presupposed an outdated theory of relations. The fact that a chair is perceived by someone, does not tell us anything about the nature of the chair:

The most general argument for realism is an application of the theory of the external or extrinsic character of relations. … The procedure of logic and mathematics—any procedure, in fact, which employs the method of analysis—is necessarily committed to the acceptance of the externality of relations. (Perry 1912, 319–20)¹⁶

Considering Russell’s crucial role in providing the neo-realists with a method, a new logic and the “most general argument for realism”, it is no surprise that Perry invited him for a visiting professorship as soon as he had the chance. When a position opened up in 1911, Perry wrote Russell a letter, trying to persuade him to come to Harvard for a year. He told him that “there is a considerable body of graduate students … with an interest in your special field”, that “[t]he younger men on this side of the Atlantic are everywhere inclining to realism” and that they all viewed him as “one of the leaders [of this] new movement of thought”.¹⁷ And in a second letter, Perry explained the neo-realists’ eagerness to get some attention from British philosophers and asked Russell (or one of his realist colleagues) to respond to their manifesto:

Do you know of any worthy Anglo-realist who could be persuaded to respond to our recent realist platform published in the Journal of Phil. etc.? We are anxious to have the thing read and noticed in England and have some of your group either agree or disagree with it in print.¹⁸

Perry’s appeal was successful. Russell had been mostly focused on James’ theory of truth after the publication of the latter’s Pragmatism (1907) but he started to shift his attention in the early 1910s. Whether or not it was caused by him reading the neo-realists’ papers, he started to explore issues (e.g., knowledge by acquaintance) that were more directly related to the presentational realism of his U.S. colleagues, explicitly referring to Perry and the “American realists” in some of these papers.¹⁹ Most importantly, he replied to Perry that he “should be glad to associate” himself “with such a valuable movement” and published an article on the new realists’ manifesto in March 1911.²⁰ In this paper, Russell affirmed his “almost complete agreement with the ‘six realists’” and their view that the “fundamental doctrine in the realistic position … is the doctrine that relations are ‘external’” (1911, 158).

5 Logic and Analysis

As can be surmised from the previous paragraphs, the realist battle against idealism was fought on many fronts. At the turn of the century, Moore dismissed Bradley’s theory of judgment, Russell challenged the idealists’ doctrine of internal relations; and Perry and Montague objected to Royce’s view that reality is mind-dependent. A more complete account of the revolt would also have included Morris R. Cohen’s logical realism, E. B. McGilvary’s perspectivist realism, Woodbridge’s Aristotelian realism, and the realisms developed by various branches of the Brentano school (e.g., Meinong, Husserl, and Twardowski) in Central Europe. Realists across the globe were dismissing the views of their predecessors and their successes evince the declining popularity of idealist philosophy.

Though it is clear that realist philosophies were on the rise, it is difficult to explain their success in purely philosophical terms. Indeed, most historians agree that none of the aforementioned realists offered a decisive philosophical argument against the idealist framework. G. J. Warnock submits that it would be “historically improper to give the impression that Idealism perished of refutation” (1958, 9), and Peter Hylton concludes that neither Moore nor Russell “had a conclusive argument against Idealism” (1990, 105; see also Griffin 1991, 364). The same can be said about the discussion in North America. Even if Perry and his colleagues were right that Royce’s objections to realism were misguided, most historians agree that the six never managed to develop a satisfying alternative (see Kuklick 2001, 258; De Waal 2012, xxiv). The neo-realists failed to develop a “presentational” realism that can adequately solve the problem of illusion, suggesting that the movement was more popular for its anti-idealist rhetoric than for its positive contributions.

It is natural, therefore, to explore non-philosophical reasons for the growing opposition to idealism. Indeed, much of the appeal of the realist movement, both in England and the United States, seems to have been its connection to the spectacular advances in logic and the foundations of mathematics. The realists had a hard time offering conclusive philosophical arguments against idealism but Russell’s work in logic and the foundations of mathematics gave the movement enough scientific credibility to sway the next generation of professional philosophers. Though realism “is not the inevitable philosophical consequence of modern logic”, it started to be “interwoven” with its development (Hylton 1990, 116; Levine 2009). Indeed, Hylton has argued that it is the “intimate link” between realism and the new logic that is “most responsible for [its] appeal” and “its influence on later analytic philosophy” (1990, 116).²¹

If the spectacular advances in logic and the foundations of mathematics are (part of) the explanation for the appeal of the realists and, by extension, the declining popularity of idealism, we can understand why Perry and his men were so eager to get Russell’s support. The Englishman was an important voice in realist debates but he was, first and foremost, one of the towering figures of the new logic. Even if there is no direct link between realism and the new logic, Russell could give the position a mathematical respectability that the six realists could have never acquired on their own. Principles of Mathematics had been received as an “imposing treatise” (Keyser 1904, 32), and Russell’s fame had only grown after the publication of Principia Mathematica. C. I. Lewis wrote that “the Principia is to intellect what the pyramids are to manual labor” (1914, 502), and Morris Cohen described the first volume as “a monument of devotion to pure thinking” (1912, 91).

The new realists needed Russell for two reasons. For one thing, they needed his logical track record because none of the American realists had contributed to the field themselves. Though some of the new realists couched their papers in logical vocabulary, it has been argued that their knowledge of logic was surprisingly superficial. Bruce Kuklick, for example, submits that Perry was largely “ignorant” of logic and never managed to use it beyond “substitut[ing] symbols for his lucid prose,” using “letters and numbers to state relations that he stated just as easily without them­” to give his work “an appearance of increased precision” (1977, 349).²² Something similar has been said about the neo-realist Holt. Although the Harvard philosopher aimed to present his theory as a consistent deductive system, some reviewers regarded his approach as little more than mathematical window dressing. Holt’s book was generally well-received because of its theory of consciousness but reviewers criticized and sometimes even outright mocked his logic. Arthur Lovejoy wrote that it is “hard to repress a suspicion that the author … is presenting a clever caricature of the abuses of the dialectical method” (1914, 669), and even the more sympathetic H. M. Kallen submitted that the “book is far from the consistent deductive system [Holt] meant it to be” (1916, 607).

Second, the realists needed Russell to justify the link between realism and the new logic because the Americans who did contribute to the development of symbolic logic were either idealists or pragmatists. At Harvard, logic was the almost exclusive domain of Royce, who was actively engaged in debates about the set-theoretic paradoxes and the foundations of geometry (see Parker and Pratt 2021, sec. 3.4). It was Royce who taught most Harvard logic courses, and it was Royce who supervised the next generation of Harvard logicians: Henry M. Sheffer and C. I. Lewis. Royce had familiarized himself with symbolic logic after attending lectures by Peirce in 1898 and spent more than a decade working on the new science, filling “dozens of notebooks with minute explorations of Boolean functions and relations” (Burch 2010, 211). And though there is little agreement about how Royce’s “achievements in mathematical logic are related to his broader philosophical ideas, and, indeed, to his idealist philosophical system as a whole” (Burch 2010, 222), it is undisputed that he quickly became one of America’s foremost experts, only matched by Peirce. Idealists such as Creighton, Bradley and Bosanquet all generally opposed symbolic logic but Royce was a remarkable exception (see Bradley 1883; Bosanquet 1885; Creighton 1898).

Russell himself also recognized that it was Royce rather than Perry or Holt, who was Harvard’s prime logician. Though he once described the philosopher Royce as a “lovable” yet “garrulous old bore” devoted to the “hopeless defense of a discredited philosophical system” (Willis 1989, 15), he had great respect for his work in logic. He thought that Royce was the only one at Harvard “to hear whispers from another world” and personally invited his colleague to talk at the International Congress of Mathematicians in 1912.²³ The respect between the two logicians was mutual, for Royce also admired Russell’s work. He studied the Principia in great detail and sent Sheffer, his most talented student in logic, to Cambridge to learn from the English master. In a letter to Russell, Royce expressed his great esteem of the latter’s work, arguing that he was doing everything “to win students” for his “most important region of research”.²⁴ It is hardly a surprise, therefore, that it was Royce who travelled to Cambridge to ask Russell to come over to Harvard “permanently as their chief professor”.²⁵

6 Mr. Apollinax

I opened this paper with the observation that Russell visited Harvard at a crucial moment in the history of American philosophy. The country’s “golden department” (Mink 1980) had lost two leading philosophers—James and Santayana—and Royce was recovering from a mild stroke. The developments outlined thus far, however, suggest that Russell’s visit was timely from an intellectual perspective as well. In the years following James’ death, Harvard philosophers had been occupied with a debate between realists and idealists and both sides had been increasingly turning to the new logic. Royce had become a self-taught expert and was steering Harvard graduates toward the new field of study. Perry and Holt were strongly advocating Russell’s approach in their publications, presenting their neo-realist movement as the scientific answer to speculative philosophy.

The main factions in Harvard’s department of philosophy, therefore, agreed that Russell would be the ideal successor to James. While Perry believed that Royce’s idealism was “outmoded and … ill equipped to serve American thought in the new century” (Kuklick 2001, 176), the two worked closely together to persuade Russell to accept a professorship at Harvard. When Royce, in January 1913, had to travel to Europe to deliver the Hibbert Lectures at Oxford, he promised Perry that he would “do whatever I can about Russell”.²⁶ And when the Englishman turned out to be “utterly immoveable for any foreign appointment”, Royce quickly sent an apology to Perry, explaining that he had “not been idle to our interests”.²⁷ Although Russell could not be persuaded to accept a permanent position, he did agree to visit Harvard for a semester in 1914. Russell understood that he had acquired an amount of fame in the United States that was “not anything like” his “reputation in England” and rightly felt that “America contains a number of people who are ready to take up my sort of work.”²⁸

Russell arrived in the United States on 13 March 1914, prompting the New York Times to write about the visit of “one of the foremost lecturers on philosophy.”²⁹ Russell had agreed to offer two courses—one on logic and one on theory of knowledge—and to the deliver the Lowell Lectures in Boston. Naturally, the visit was eagerly anticipated by the Harvard community. In a letter to Russell, Santayana wrote that

… there is no one whom the younger school of philosophers in America are more eager to learn of than of you. You would bring new standards of precision and independence of thought which would open their eyes, and probably have the greatest influence on the rising generation of professional philosophers.³⁰

Victor Lenzen, a Berkeley student who had acquired a scholarship to travel to the East coast for the occasion, wrote that the English logician was viewed as “an almost superhuman person” by the students, arguing that it is impossible to “adequately describe the respect, adoration, and even awe which he inspired” (1971, 4). The American-born poet T. S. Eliot, who attended Russell’s course, even wrote a poem—Mr. Apollinax—describing how the Harvard community behaved in the presence of the famous English philosopher.³¹

Russell’s visit was not only timely from an American perspective. His visit came at a crucial moment in his own career as well. After finishing his share of the Principia, he had started to apply his logic to more traditional philosophical problems, actively pushing for what he was now calling a “scientific philosophy”. Russell argued that the work of Cantor and Peano had made possible “a solid philosophy of space, time, and motion” (1911, 40) and he applied his theory of relations to the problem of universals in his 1911 Aristotelian Society address (Russell 1912). “In everything Russell wrote at this time”, his biographer Ray Monk has argued, there was:

… an almost evangelical fervour in his advocation of the ‘scientific method in philosophy’. For Russell, it was not just a belief as to the best way to pursue philosophical investigations, it was a cause, a fight … against various forms of philosophical wrongheadedness. (Monk 1996, 338)³²

It is no coincidence, therefore, that Russell’s “scientific philosophy” and its corresponding “method of logical analysis” became the central theme of his period in the United States. His Lowell Lectures Our Knowledge of the External World aimed to develop a “genuinely scientific philosophy” and reach a general account of its “logical-analytic method” (1914d, 14, 26, 51).³³ Outside Harvard, Russell mainly read his paper “Mysticism and Logic”, arguing for a “truly scientific philosophy” that is “more humble, more piecemeal, … and more capable of accepting the world” than the philosophies of the past (1914a, 32). In both of these lectures, Russell’s central message was that philosophy should become “scientific” in two distinct but related ways, both of which reinforced developments that had been set in motion at the turn of the century. First, Russell believed that philosophy should become a science—a collaborative, objective enterprise which aims “at results independent of the tastes and temperament of the philosopher who advocates them” (Russell 1914d, vx). Whereas the idealists of the nineteenth century had mostly been solitary system builders who aimed to unify scientific, moral, and spiritual knowledge (Section 3), the scientific philosopher should adopt “piecemeal, detailed, and verifiable results” over “large untested generalities recommended only by a certain appeal to the imagination” (1914d, 2). Or, as Russell summarized his point: “The failure of philosophy hitherto has been due in the main to haste and ambition: patience and modesty, here as in other sciences, will open the road to solid and durable progress” ([1914] 1917, 93).

Second, Russell’s philosophy aimed to be scientific in offering a new perspective on the nature of philosophical problems. In addition to the view that scientific philosophers should employ a scientific approach and a “logical-analytic method” in answering philosophical questions, he aimed to change our ideas about what philosophical questions are. Philosophy, Russell argued, has a definite domain which distinguishes it from the province of the special sciences but it is the same domain that has been explored by logicians: it “is concerned with the analysis and enumeration of logical forms” and is thereby “indistinguishable from logic as that word has now come to be used” ([1914] 1917, 84–85).³⁴ Whereas the sciences aim to answer questions that are decided by empirical evidence, philosophy investigates the logical forms that allow us to meaningfully talk about the world. In his Lowell lectures, Russell even boldly claimed that “every philosophical problem, when it is subjected to the necessary analysis and purification, is found either to be not really philosophical at all, or else to be … logical” (1914d, 26).

7 Sheffer, Lewis, and Whitehead

Russell returned to Cambridge in June 1914, three weeks before Gavrilo Princip assassinated the heir presumptive to the Austro-Hungarian throne. The global war that ensued completely transformed the American intellectual climate. The United States was not officially involved until 1917 but anti-German sentiments started dominating public debates when a German U-boat sunk the RMS Lusitania in May 1915. Many Harvard philosophers played an important role in discussions about the country’s position in the conflict. Unlike Russell, who advocated a pacifist position and was eventually imprisoned for violating the Defence of the Realm Act, most of them urged the government to enter the war, agreeing that Germany had been the aggressor. Both Royce and Perry, for example, wrote multiple books and pamphlets explaining their views about America’s duties toward Europe (Royce 1914, 1916; Perry 1916, 1918).³⁵

Somewhat surprisingly, Harvard’s political discussions about the war quickly got entangled with the philosophical debate between idealists and realists. The idealists had been building on German intellectual movements (see Section 2) and several Harvard philosophers were eager to point this out in their anti-German propaganda. Perry, for example, drew a clear link between German militarism and the development of nineteenth century speculative philosophy, insisting that “Absolute Idealism” played “a major role in present events” (1918, 174):

[I]t is characteristic of Germans to provide a philosophical justification for what they do. The philosophy to which they commonly appeal for this purpose is … ‘Absolute Idealism’. English, French and American adherents of this philosophy now find themselves in a somewhat awkward predicament. The doctrines which they have for a generation proved and proclaimed are now used as the premises for policies which their moral enlightenment and national loyalty compels them to denounce…. Not only does the Kaiser quote Kant, but the Gelehrte, the learned men themselves, insist upon linking present German policy with the teachings of their most exalted thinkers. (Perry 1918, 417–18)

Santayana, now based in Europe, published a book connecting Germany’s political “egotism” to the idealist view that the world is mind-dependent. Though Santayana did not go as far as to claim that “German philosophers are responsible for the war”, he did want to convey that the idealists had “shared and justified prophetically that spirit of uncompromising self-assertion and metaphysical conceit which the German nation is now reducing to action” (1916, 7).

The war, therefore, dealt another, perhaps final, blow to speculative philosophy at Harvard, turning idealism into a politically suspect world view. By “labeling a conception, a policy, or a mode of conduct ‘German’”, Frank Thilly wrote a few years after the end of the conflict, philosophers were able “to put the quietus on it: whatever was German was wrong” (1920, 185). Much as German philosophers had framed the war as a Kulturkrieg, Harvard academics presented it as a “conflict of ideas”—as a war in which “general ideas and ultimate values … are at stake” (Perry 1918, 2). Perry argued that absolute idealism had sold Germans “the doctrine of the infallible state-personality” and that Russell’s doctrine of external relations, by contrast, had liberated scholars and given rise to a “philosophy which underlies individualism, social democracy, and humanitarianism” (1918, 376).³⁶

It is only natural, therefore, that the war accelerated philosophical developments that had been brewing since the turn of the century. After the armistice of 1918, Harvard philosophy became increasingly focused on technical subjects such as logic, philosophy of science and epistemology—employing a conception of scientific philosophy that Russell had promoted during his 1914 visit.³⁷ And the department’s hiring decisions played an important role in accelerating this transition. Even before his visit, we have seen, Russell had been the faculty’s prime candidate to become James’ successor as the crown jewel of Harvard philosophy. After 1914, Harvard philosophers were even more convinced that they wanted Russell. The new department chair James H. Woods wrote that he had “hardly seen any other visitor exerting such a deep and wholesome influence on some of the best students”. Perry urged that they had to try “by hook or crook [to] attach [Russell] to ourselves”; and William Ernest Hocking wrote that he knew of “no thinker, at present, who surpasses him in the keenness, vigor, and originality of his work in logic”.³⁸ It is no surprise, therefore, that when Royce died in 1916, the New York Times published an article suggesting that that the vacant post would be offered to Russell.³⁹

When Harvard President Abbott Lawrence Lowell learned that Russell could not be appointed because the British government refused to issue a passport to a convicted man, the department was deeply disappointed. Yet the philosophers did not give up on their search for a top-notch logician and started looking for alternative candidates that could help Harvard attract “many of the cleverest of the youth with predilections for logic”.⁴⁰ At first, the department hired H. M. Sheffer and Ralph Monroe Eaton as instructors, both of whom would stay at Harvard until the end of their careers. The former had been Royce’s student and was known as “Russell’s most enthusiastic representative at Harvard” (Floyd 2021, 33). The latter had just completed a dissertation on “The Method of Induction” and would later publish General Logic, one of the first American textbooks to include an introduction to symbolic logic (Eaton 1931). A few years later, Harvard managed to attract C. I. Lewis (1921) and A. N. Whitehead (1924), thereby appointing two of the best-known logicians in the Anglophone world. Lewis had just published his seminal A Survey of Symbolic Logic; Whitehead was the co-author of Principia Mathematica and had become an influential voice in philosophy of science (Whitehead 1920; Verhaegh 2024a). The latter’s appointment was made possible by a group of Harvard academics who called themselves “the Royce club” and who regularly met to discuss issues in logic and philosophy of science. Lowell had been stalling Whitehead’s appointment because of the university’s financial situation but was persuaded to hire the logician after the biochemist L. J. Henderson, a former student of Royce, made sure that the funds were supplied by an external donor (Lowe 1990, 132–33).⁴¹

Incidentally, this is also the period when Harvard philosophers helped generate new attention for Peirce’s contributions to the development of logic and scientific philosophy. Lewis’ (1918, ch. 1) history of symbolic logic paid special attention to Peirce’s work, and Harvard acquired the latter’s papers, reserving funds to have a group of scholars organize and catalogue them.⁴² Russell was asked to edit the first volumes after Royce’s death in 1916 but was unable to come to Harvard for the above-mentioned reasons. Eventually, Morris R. Cohen published a selection of Peirce’s papers in 1923. The first six volumes of the collected papers, edited by Charles Hartshorne and Paul Weiss, both recent Harvard graduates, appeared between 1931 and 1935.

8 The Harvard School

As a result of the appointments of Sheffer, Lewis, and Whitehead, Harvard quickly became known as a central hub for symbolic logic in the United States. Roy Wood Sellars wrote about the “efflorescence of mathematical logic so characteristic of Harvard” (1927, 513); Palmer and Perry boasted about the department’s “unquestioned leadership in [the] field” (1930, 27); and Charles Morris’ overview of “recent American scientific philosophy” described Harvard as “the center of formal logic in the United States” (1935, 146), mentioning Sheffer, Lewis, Eaton, Huntington, and several recent Harvard graduates, including C. H. Langford, Susanne Langer, and W. V. Quine as some of its most important representatives.⁴³ Whereas Harvard instructor Harry Costello, in the early 1910s, had had to give up his logic class because “symbolic logic excited little interest” and attracted only “classes of three” (Costello 1957, 245), the new generation “looked forward to a new philosophical era, that was to grow from logic and semantics” (Langer 1964, 306).

Harvard’s new hires and reputation in logic also affected its curriculum. Tables 1a and 1b compare the department’s course offerings in logic in 1910–1911 and 1925–1926, showing how its curriculum expanded in just fifteen years’ time. While Harvard offered three logic courses taught by Royce and his assistant Costello in 1910, at least one of which was actually a class in what we would now call philosophy of science, the number of logic courses significantly increased after the department hired Sheffer, Lewis, and Whitehead.⁴⁴

Nor was the new generation exclusively interested in logic. Many of them also embraced Russell’s more general ideas about philosophical method and the nature of philosophical problems. Langer adopted Russell’s “method of logical analysis” in her dissertation “A Logical Analysis of Meaning” (1926, 1) and advocated an “analytic” approach to philosophy in her 1930 book The Practice of Philosophy.⁴⁷ She advocated Russell’s thesis that philosophy “is concerned with the analysis and enumeration of logical forms” and explicitly relied on Russell’s analysis, extensively quoting from “Bertrand Russell’s admirable lucid exposition of logical forms” in his 1914 Lowell lectures (1930, 91–92). Quine wrote a dissertation in which he tried to improve Whitehead and Russell’s treatment of classes and relations and later remembered that it had been Russell, not his philosophy teachers, who “whetted [his] appetite for cosmic understanding” (1986, 7).⁴⁸

9 The Harvard School and the Analytic Turn

In arguing that Harvard became well known for its “school of logic”, I do not want to suggest that Harvard philosophers significantly impacted the development of logic itself. Whitehead had largely turned to his process philosophy in his American years, Perry had never been much of a logician (see Section 5), and Sheffer published too little to influence the development of logic outside Emerson Hall, except for the recognition for his now famous “stroke” function, which Whitehead and Russell used in the second edition of Principia Mathematica. Indeed, Quine would later complain that “American philosophers associated Harvard with logic because of Whitehead, Sheffer, Lewis, and the shades of Peirce and Royce” but that “the action was in Europe”, where the work of Ackermann, Bernays, Gödel, Herbrand, Löwenheim, Skolem, and von Neumann was revolutionizing the field (1986, 9, my emphasis).

Nor I do not want to suggest that Harvard’s department of philosophy in the late 1920s was the country’s first analytic department. Though the philosophical climate had professionalized and shifted in focus, contributing to the development of a more scientific approach to philosophy, Harvard philosophers were still promoting very different conceptions of philosophy. Lewis spoke about “a new movement” that, sparked by the “revolutionary advances in logic, mathematical, and physical theory”, sought to develop philosophy “in the direction of greater comprehensiveness and increased rigor” (1925, 410). But the philosophers’ conception of what it means to develop a “scientific” or an “analytic” philosophy was still very much in flux. Even Langer, one of the first U.S. philosophers to use the term in print, still had quite a different conception of analytic philosophy, identifying it with the views and approach of, among others, Meinong, Husserl, Peirce, Russell, and Broad (1930, 21).

What I do want to claim, is that Harvard philosophy drastically changed in the years after the war and thereby helped pave the way for the analytic turn, which was further stimulated by the logical empiricist wave of logical-analytic philosophy that hit American shores in the 1930s. The Harvard School functioned as the main intellectual bridge between American and European groups of scientific philosophers and significantly contributed to the reception of logical empiricism in the 1930s and 1940s. When Herbert Feigl spent a year at Harvard in the 1930–1931 academic year, he encountered a group of logicians and philosophers, including Lewis, Quine, and Langer, who were very susceptible to his message. Feigl had intense discussions with Lewis, whose recently published Mind and the World Order he thought was “barely distinguishable from our positivism”. And he attended Langer’s Monday night logic meetings, writing to Schlick that it reminded him of the Vienna Circle.⁴⁹ While some Harvard professors and graduates, including Lewis and Sheffer, eventually became sceptics of the logical empiricist movement, several other Harvard philosophers were significantly impacted by it. Quine visited Carnap in Prague and considered himself “Carnap’s disciple” for much of the 1930s (Quine [1970] 1976, 41); Goodman completed a dissertation that was significantly influenced by Carnap’s Der Logische Aufbau der Welt (1929). And when Carnap first lectured on his Logische Syntax at Harvard in the summer of 1936, his course was attended by many of the new generation of philosopher-logicians, including Henle, Langer, Leonard, Parry, Quine, and Weiss.⁵⁰

Conversely, the Harvard School would also play an important role in the logical empiricists’ decision to seek refuge in the United States. Carnap, for instance, explicitly mentioned the Harvard logicians when he started to develop plans to emigrate, talking about a “Lewis-Sheffer circle” in a letter to Felix Kaufmann. Two young Harvard logicians—Quine and the aforementioned Parry—had visited him in Prague in the early 1930s and had led him to conclude that “people are thoroughly engaged with logic” at Harvard University.⁵¹ Something similar applies to Reichenbach, who read Lewis’ Mind and the World Order and was struck by the similarities to his own work. The two developed a correspondence in the early 1930s and this likely played a role in Reichenbach’s growing conviction that the United States would be a more natural home for his “scientific philosophy than Europe” where “mystical-metaphysical speculation is still regarded as the true philosophy”.⁵²

10 Conclusion

In this paper, I have reconstructed the development of the Harvard school of logic through the lens of Russell’s 1914 visit, discussing a range of intellectual and institutional changes that contributed to the growing popularity of the “logical-analytic method” within Harvard’s department of philosophy. I have both highlighted and contextualized the impact of Russell’s visit by examining multiple factors that contributed to the rise of the Harvard school, including (1) the rapid professionalization of American philosophy, (2) the idealists’ focus on logic in their attempts to demarcate philosophy as an independent discipline, (3) the rapid advances in symbolic logic, (4) the realist revolt against idealism and speculative philosophy, (5) the new realists’ efforts to employ these developments to brand their view as a scientific alternative to idealism, (6) Royce’s introduction of symbolic logic to the Harvard philosophy curriculum, (7) the growing opposition to German philosophy during the First World War, and (8) Harvard’s hiring decisions between 1915 and 1924. Russell, these considerations show, was the right man at the right time in more than one respect: He visited the department when several key players had been turning to the new logic, when he himself had started to push for a scientific philosophy, and when the department was seeking a new role model after the loss of several key members of faculty.

Considering Russell’s impact on Harvard philosophy and the department’s later role in facilitating communication between European and American scientific philosophers, it seems hardly an exaggeration to conclude—as Charles Morris did—that it was primarily “the influence of Bertrand Russell” that “facilitated the building of intellectual bridges” between the two communities in the late 1920s (1935, 148). Indeed, when Russell returned to Harvard in 1929, he encountered a radically altered intellectual culture. Harvard was now the epicenter of professionalized philosophy and the department was populated with faculty and graduate students who had taken his central message to heart. Russell met Lewis, the rising star of American philosophy, and he was reunited with Sheffer, who was training the next generation of American logicians. And because of the department’s status in the United States, the approach had already started to spread to other universities, as always eager to hire Harvard graduates.⁵³ Even in Texas, Russell joked in a letter to his wife, philosophy departments were “full of people who … read all three vols. of Principia Mathematica”.⁵⁴ Within just a few decades’ time, Harvard had witnessed an incredible transformation. It had evolved from a small religious college, to a rapidly growing university employing world-famous intellectuals like James and Santayana, to a strongly professionalized research university whose philosophers were internationally known for their logical-analytic approach.

Acknowledgements

This research is funded by the European Research Council (ERC StG 2021, 101039904) and the Dutch Research Council (NWO VI.Vidi.201.115). Most of this research was done in 2022, as part of a Bertrand Russell Visiting Professorship at McMaster University. I would like to thank everyone who helped me feel welcome at McMaster and the Russell Research Center, in particular Rabia Awan, Kenneth Blackwell, Andrew Bone, Jessica Bouchard, Mark Johnstone, Alex Klein, Sandra Lapointe, Johannes Steizinger, and Donovan Wishon. I am also indebted to Sébastien Gandon, Ties van Gemert, Joel Katzav, Sangam McDuff, Matthias Neuber, Jan Vrhovski, and the Exiled Empiricists team for their comments on earlier versions of this paper. Parts of Sections 1 and 8 have appeared elsewhere in a slightly different form (Verhaegh 2024b, secs. 2–3).